CN104808036A - Magnetically coupled dc current sensor - Google Patents
Magnetically coupled dc current sensor Download PDFInfo
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- CN104808036A CN104808036A CN201510036098.0A CN201510036098A CN104808036A CN 104808036 A CN104808036 A CN 104808036A CN 201510036098 A CN201510036098 A CN 201510036098A CN 104808036 A CN104808036 A CN 104808036A
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- driving voltage
- current
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- primary side
- voltage
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R1/00—Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00
- G01R1/20—Modifications of basic electric elements for use in electric measuring instruments; Structural combinations of such elements with such instruments
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/18—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using conversion of DC into AC, e.g. with choppers
- G01R19/20—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using conversion of DC into AC, e.g. with choppers using transductors, i.e. a magnetic core transducer the saturation of which is cyclically reversed by an AC source on the secondary side
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- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Measurement Of Current Or Voltage (AREA)
- Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)
Abstract
A method for measuring current includes passing a DC current through the primary side of a transformer and driving the secondary side of the transformer with an AC voltage, wherein the current in the secondary side of the transformer reaches a plateau. The current in the secondary side of the transformer is measured during the plateau, wherein the measured current is proportional to the DC current.
Description
claim of priority
Subject application advocates that the title of the Isaac Koln (Isaac Cohen) of applying on January 24th, 2014 is the U.S. Provisional Patent Application case 61/931 of " magnetic coupling DC current sensor (MAGNETICALLY COUPLED DC CURRENT SENSOR) ", the right of priority of 373, described temporary patent application case is incorporated herein by reference for disclosed all objects.
Technical field
Subject application relates to DC current sensor.
Background technology
Isolation DC current sensor remote sense or measurement DC electric current.Some isolation DC current sensor comprises the transformer or analog with primary side and primary side.Primary side has a circle or only some circles and for making DC electric current pass through usually.The DC electric current flowing through primary side produces the field finally inducing electric current in primary side, and described electric current is called secondary current.Measure the secondary current that produces in the primary side of transformer and provide described secondary current as instruction DC electric current or the output with DC current in proportion.For there is not physical connection between the circuit produced through measuring electric current and DC current sensing circuit in one of benefit of this type of isolation DC current sensor.
Summary of the invention
Method for measuring electric current comprises makes DC electric current by the primary side of transformer and the primary side using AC voltage driven transformer, and the electric current in the primary side of wherein transformer reaches maintenance level (plateau).During maintenance level measuring transformer primary side in electric current, wherein through measuring electric current and DC current in proportion.
Accompanying drawing explanation
Fig. 1 is the signal explanation of prior art current sensor.
Fig. 2 A is the chart of the example of the driving voltage of Fig. 1.
Fig. 2 B is the chart of the example in response to the desirable secondary current in the current sensor of Fig. 1 of driving voltage and DC electric current.
Fig. 2 C is the chart of the example in response to the actual secondary current in the current sensor of Fig. 1 of driving voltage and DC electric current.
Fig. 3 is the schematic diagram of the example of the twin-core current sensor comprising the dynamic electric voltage supply producing driving voltage.
Fig. 4 is the detailed maps of the example of current sensor.
Fig. 5 is the schematic diagram of the example of the current sensor with single core or transformer.
Fig. 6 is the process flow diagram of the example of method for measuring electric current.
Embodiment
Fig. 1 is the explanation of prior art current sensor 100.Current sensor 100 comprises two cores, and it is individually called the first core 102 and the second core 104.Ideally, core 102,104 has unlimited magnetoconductivity.But in actual applications, core 102,104 has very high magnetoconductivity.Carry DC electric current I
dCconductor 108 extend through core 102,104.As shown in Fig. 1, conductor 108 extends through the first core 102 in a first direction and conductor 108 extends through the second core 104 in a second direction.
Be wound around the first core 102 with the first winding 110 and be wound around the second core 104 with the second winding 112.For purpose of explanation, only show some circle windings 110,112 in FIG, but, in most of example, there is many circles in each core, such as hundreds of or thousands of circle.Winding 110,112 is connected in series, and makes by the DC electric current I in the first winding 110
dCthe electric current induced is contrary with the electric current induced in the second winding 112.Winding 110,112 is coupled or is otherwise connected to and produces driving voltage V
dvoltage supply 114.In addition, winding 110,112 is coupled to bridge 120.In the example of fig. 1, driving voltage V
dfor the square wave shown in such as chart 2A.Under ideal case, driving voltage V
dthere is the work of 50% in proper order, make driving voltage V
dduring the first half of its circulation, there is the first polarity and in the latter half of period of described circulation, there is opposite polarity.
Secondary current I
sin response to driving voltage V
dand DC electric current I
dCflow through winding 110,112.Under ideal case, secondary current I
sin positive peak electric current I
p+and negative peak electric current I
p-value place reach peak value, I
p+and I
p-all there is I
dCthe amplitude of/N, wherein N is the turn ratio in each in winding 102,104.In the example of fig. 1, conductor 108 extends through core 102,104, so turn ratio N is the number of turn on winding 110 and 112.By bridge 120 rectification secondary current I
sand measure secondary current I by current measuring device 122
s.In the ideal case of Fig. 2 B, through rectification secondary current I
sto be perfect DC electric current, wherein mean value equals DC electric current I
dCdivided by the number of turn in winding 110,112.
In real-world conditions, the magnetoconductivity of core 102,104 is not unlimited, and leakage inductance exists and winding 110,112 has resistance.Thus, secondary current I
snon-constantly follow DC electric current I
dC.Secondary current I under non-genuine situation
sexample by the diagrammatic representation of Fig. 2 C.As shown in Fig. 2 C, secondary current I
swaveform be trapezoidal in fact but not as being square in the ideal case of Fig. 2 B.The trapezoidal waveform of Fig. 2 C is at the secondary current I with Fig. 2 B
sidentical positive peak electric current I
p+and negative peak electric current I
p-place has maintenance level 126 and 128.If carry out rectification to the trapezoidal waveform of Fig. 2 C, so gained waveform will not be pure DC electric current and it will be not equal to I
dC/ N.Therefore, based on through rectification secondary current I
sgained current measurement will not be correct.
The one or both place of example embodiment in maintenance level 126,128 of current flow sensor samples or otherwise measures secondary current I
s.By for measuring timing with consistent with the one or both in maintenance level 126,128, at secondary current I
sreach the maintenance level cycle t of maintenance level
pperiod realizes measuring.In some example embodiment, timing and the driving voltage V of measurement
dfrequency dependence, make measure at maintenance level cycle t
pperiod occurs.In other example embodiment, during maintenance level 126,128, monitor secondary current I
sand measure when reaching maintenance level 126,128.For example, monitor (displaying) can monitor secondary current I
sand at secondary current I
sderivant (derivative) be zero or change in fact time (this indicates maintenance level 126,128) produce perform measure instruction.In other situation, monitor can monitor secondary current I not having period in vicissitudinous cycle (this indicates maintenance level)
s.The method of above-described supervision maintenance level 126,128 is applicable to all current sensor embodiments described herein.
Driving voltage V in conventional current sensors
dbe static, this represents driving voltage V
dfrequency and amplitude be constant.In this type of situation, when DC electric current I
dCtime larger, secondary current may not reach maintenance level.For example, secondary current I
svalue I can may not be reached in not having the form of the trapezoidal wave of maintenance level or its peak value
dC/ N.At driving voltage V
dhigher to make to be derived from high DC electric current I
dCthe secondary electric current I of height
scan reach in the situation of maintenance level, sensor 100 may due in DC electric current I
dCfor producing too much maintenance level cycle t time low
pand use excessive power.For example, driving voltage V
dstatic amplitude can keep high, this produces long maintenance level cycle t
p, it is long that the necessary maintenance level cycle is measured in its comparable execution.Produce long maintenance level cycle t
pproblem be: driving voltage V
dremain high, this consumes too much power.Current sensor described herein comprises dynamic driving voltage, and it overcomes the problems referred to above existing for static drive voltage.
In order to comprise dynamic electric voltage supply 302, (it produces driving voltage V to Fig. 3
d) the schematic diagram of example of twin-core current sensor 300.Twin-core sensor 300 makes it possible to do not considering DC electric current I
dCdirection when measure DC electric current I
dC.In some instances, voltage supply 302 is in response to secondary current I
sand change or modulation driving voltage V
damplitude.In other example, voltage supply 302 is in response to secondary current I
sand modulation or change driving voltage V
dfrequency.In other example, voltage supply 302 is in response to secondary current I
sand modulate driving voltage V
damplitude and frequency.
DC electric current I measured by current sensor 300
dC, DC electric current I
dCbe illustrated as the primary side 306 (or referred to as " elementary 306 ") of leap two-stub transformer T1 in figure 3 and be coupled.In fact, DC electric current I
dCbe generally the DC electric current flowed in the conductor, wherein said conductor is coupled to and produces DC electric current I
dCcircuit.Transformer T1 in Fig. 3 is described as single assembly.Such as, but in other embodiments, transformer T1 is two devices, has the device of two cores 102,104 of Fig. 1.Therefore, primary side 306 can be the conductor through two cores shown in such as Fig. 1.
Secondary 308 of transformer T1 is coupled to the output 310 of voltage supply 302, its outputting drive voltage V
d.Driving voltage VD is square wave, and it has 50% working cycle of the diagrammatic representation as Fig. 2 A in the example of fig. 3.Secondary 308 are coupled to measurement secondary current I
scurrent measuring device 314.Current sensor 314 produces instruction and DC electric current I
dCproportional secondary current I
soutput signal.In some instances, the output signal of current measuring device 314 is voltage, and in other example, outputs signal as digital signal or electric current.In examples more described below, current measuring device 314 is included in maintenance level cycle t
pperiod measures secondary current I
ssampling and holding circuit or other circuit.
By the secondary current I measured by current measuring device 314
svalue feed back to voltage supply 302, voltage supply is 302 in response to secondary current I
sand produce driving voltage V
d.In some instances, voltage supply 302 produces maintenance level peak value t
p(Fig. 2) the driving voltage V in predetermined restriction is maintained
d.For example, when DC electric current I
dCduring rising, the decreased duration of maintenance level 126,128, this can shorten and can perform secondary current I wherein
scycle of measurement.In some instances, when DC electric current I
dCwhen rising too high, maintenance level 126,128 disappears.Modulation or otherwise change driving voltage V
dto maintain maintenance level 126,128.When DC electric current I
dCduring rising, secondary current I
salso rise.Secondary current I
srising cause driving voltage V
drising to maintain maintenance level 126,128.
When DC electric current I
dCduring decline, secondary current I
salso decline, this causes maintenance level cycle t
pincrease.Maintenance level cycle t
pincrease not required and can largely owing to high driving voltage V
d, high driving voltage V
dconsume unwanted power.Sensor 300 passes through at secondary current I
sdriving voltage V is reduced during decline
dovercome this problem.Therefore, sensor 300 does not consume at secondary current I
sfor producing high driving voltage V time low
drequired power.
In other embodiments or except above-described example, voltage supply 302 can in response to secondary current I
schange driving voltage V
dfrequency.For example, as secondary current I
sfor time low, driving voltage V can be increased
dfrequency, this is because make secondary current reach maintenance level 126,128 need less time.As secondary current I
sfor time high, driving voltage V can be reduced
dfrequency to provide for secondary current I
sreach the time of maintenance level 126,128.
Various method can be adopted to monitor secondary current I
sand change driving voltage V
d.In some instances, driving voltage V
damplitude and secondary current I
sdirectly related.For example, driving voltage V
dfor secondary current I
sfunction, such as linear function.In other example, scale factor is multiplied by secondary current I
sor driving voltage V
d.Therefore, secondary current I
sincrease or reduction cause driving voltage V
dproportional increase or reduction.Identical situation is applicable to wherein in response to secondary current I
schange driving voltage V
dthe example of frequency.
Fig. 4 is the more detailed maps of the example of twin-core current sensor 400.Current sensor 400 comprises the first transformer T2 and the second transformer T3.First transformer T2 has with elementary 406 series coupled of the second transformer T3 elementary 404.DC electric current (I to be measured
dC) flow through elementary 404,406 of two transformers T2, T3.Sensor 400 comprises the first driver 410 and the second driver 414, first driver 410 is coupled to secondary 412 of the first transformer T2 and the second driver 414 is coupled to secondary 416 of the second transformer T3.As shown in Fig. 4, transformer T2, T3 are configured and make its magnetization contrary.Secondary 412 of first transformer T2 has in response to DC electric current I
dCand first the level electric current I flowed through wherein
s1.Similarly, secondary 416 of the second transformer T3 have in response to DC electric current I
dCand the second subprime electric current I flowed through wherein
s2.
First driver 410 comprises the transistor Q1 with transistor Q2 series coupled.The transistor described in Fig. 4 is used as switch and other switching mechanism can be used to replace transistor.Transistor Q1 and transistor Q2 is in the coupling of node N1 place, and node N1 is coupled to secondary 412 of the first transformer T2.The grid of transistor Q1, Q2 is coupled by phase inverter 420.Therefore, transistor Q1, Q2 is in inverse state (opening or closing).The input of phase inverter 420 and the grid of transistor Q2 are coupled to clock 422, and clock 422 produces the same or similar clock signal of clock signal with Fig. 2 A.Clock signal in the example of Fig. 4 is with working cycle D operation, and working cycle D can be 50% and has the amplitude being enough to cut off and connect transistor.Based on described circuit, transistor Q2 operates with working cycle D and transistor Q1 operates with working cycle 1-D.As described above, working cycle D is 50% in some instances, so working cycle 1-D is also 50%.
Second driver 414 is similar to the first driver 410 and is included in transistor Q3 and the transistor Q4 of node N2 place series coupled.Node N2 is coupled to secondary 416 of the second transformer T3.The grid of transistor Q3, Q4 is coupled by phase inverter 424.The input of phase inverter 424 and the grid of transistor Q3 are coupled to clock 422.Therefore, transistor Q2 and Q3 connects together and cuts off and transistor Q1 and Q4 connects together and cut off.Result is: a transformer is by DC electric current I
dCcharge and another transformer that simultaneously resets.
Driver 410,414 is coupled to the dynamic electric voltage supply 430 producing positive driving voltage V+ and negative driving voltage V-, wherein in response to the secondary current I of transformer T2, T3
s1, I
s2amplitude and/or the frequency of driving voltage V+, V-are set.As shown by the configuration of driver 410,414, secondary 412,416 of transformer T2, T3 has the positive driving voltage V+ or negative driving voltage V-that are applied to it.More particularly, when node N1 is coupled to positive driving voltage V+, node N2 is coupled to negative driving voltage V-, and vice versa.Therefore, a transformer is only being had to be in saturated sometime.In voltage supply 430 and can be there is certain between node N1, N2 lose, but, in this example, think that driving voltage V+, V-are applied to node N1, N2 and do not consider any loss.
Secondary 412,416 are coupled to bridge 434, and bridge 434 is coupled to divert shunt resistor R
s.First level electric current I
s1and second subprime electric current I
s2flow through bridge 434 and produce and cross over divert shunt resistor R
sshunt Voltage V
s, Shunt Voltage V
sinstruction secondary current I
s1, I
s2and/or with secondary current I
s1, I
s2proportional.Divert shunt resistor R
sbe coupled to sampling and holding circuit 440, sampling and holding circuit 440 comprise interrupteur SW 1 and capacitor C1 in the example in figure 4.The state of interrupteur SW 1 is by clock 422 and postpone 442 controls.Postpone 442 to make it possible to cross over divert shunt resistor R in precise time sampling
sshunt Voltage V
s.In certain aspects, delay is dynamic, this is because its sampling during changing to realize maintenance level in response to the frequency of clock 422.As described above, sample at secondary current I
s1, I
s2maintenance level during occur, this provides DC electric current I
dCmeasurement accuracy.When interrupteur SW 1 closes, sampled by capacitor C1 and keep crossing over sense resistor R
ssensing voltage V
s.
The voltage crossing over capacitor C1 is the output voltage V of current sensor 400
oUT.By output voltage V
oUTfeed back to voltage supply 430, wherein voltage supply 430 is in response to output voltage V
oUTand modulation or change driving voltage V+, V-.The example of Fig. 4 comprises the scale factor K provided by amplifier 448, and amplifier 448 is by output voltage V
oUToutput voltage V is adjusted in proportion before being input to voltage supply 430
oUT.Secondary current I
s1, I
s2and the relation between driving voltage V+, V-is linear in fact, so sample K value can be used as the magnification of amplifier 448.More particularly, the major parameter of transformer T2, T3 is saturated leakage, saturated leakage be essentially non-time-varying and non-temperature become.Resistance in secondary 412,416 is non-time-varying and temperature is interdependent, but the impact of temperature variation is inessential and only affects driving loss and do not affect accuracy.Therefore, because the impact of pulsactor is most important, so only use the linear-apporximation correction function of gain factor K and fixing initial voltage V0 (described below) to be usually enough to operation sensor 400.
The example of the sensor 400 of Fig. 4 comprises the initial voltage V0 of the feedback of adding to voltage supply 430.Initial voltage V0 supplies 430 in DC electric current I for causing voltage
dCminimum or generation driving voltage V+, V-when not existing minimum voltage input.When not adding initial voltage V0, driving voltage V+, V-can drop in DC electric current I
dCthe level of decline or prevention current sensor 400 proper operation when not existing.In some instances, minimum driving voltage V
ddetermined by the resistance of the winding in secondary 412,416.
Fig. 5 is the schematic diagram of the example of the current sensor 500 with single core or transformer T4.Be different from above-described current sensor, current sensor 500 is not two-way and only measures the DC electric current I flowed in one direction
dC.Current sensor 500 has single transformer T4, so DC electric current I
dCflow only through elementary 502 of a described transformer T4.Transformer T4 secondary 504 side be coupled to divert shunt resistor R
s, divert shunt resistor R
sby secondary current I
sconvert Shunt Voltage V to
s.Shunt Voltage V is measured by voltage measuring apparatus 510
s.As described above, at secondary current I
smaintenance level during perform voltage measurement.Voltage measuring apparatus 510 has provides instruction DC electric current I
dCthe output of signal (such as, voltage).Positive voltage supply 514 and negative voltage supply 516 are coupled in described output, and positive voltage supply 514 supplies positive driving voltage V+ and the negative driving voltage V-of negative voltage supply 516 supply.In some instances, positive voltage supply 514 and negative voltage supply 516 are the single voltage supply as shown in Fig. 3.
Driving circuit 520 is coupled in the opposite side of secondary 504, positive voltage supply 514 and negative voltage supply 516.Driving circuit 520 be included in node N4 place coupling transistor Q5 and transistor Q6, node N4 be coupled to secondary 504 of transformer T4.Transistor Q5 is coupled to positive driving voltage 514 and transistor Q6 is coupled to negative voltage supply 516 by restrictor 522.In some instances, restrictor 522 is set to the current value of the saturation current approximating transformer T4.
The grid of transistor Q5, Q6 is driven by the clock 526 of the square wave produced as shown in Fig. 2 A.Clock 526 is coupled to the grid of transistor Q5 and is coupled to the grid of transistor Q6 by phase inverter 528.Therefore, the grid of working cycle D driving transistors Q5 is used and the grid of use working cycle 1-D driving transistors Q6.In the example of fig. 5, working cycle D is 50%, so with same working cycle driving transistors Q5, Q6.
Current sensor 500 uses secondary 504 of positive driving voltage V+ driving transformer T4 during duration D.During this cycle, DC electric current I
dCinduce secondary current I
s, secondary current I
sflow through divert shunt resistor R
s.When the voltage crossing over divert shunt resistor RS reaches maintenance level, voltage measuring apparatus 510 measures described voltage.Therefore, the voltage at maintenance level place corresponds to I
dCthe secondary current I of/N
s.During the cycle of 1-D, negative driving voltage V-is coupled to secondary 504 by restrictor 522.This is coupled through and forces transformer T4 to reset close to the saturated transformer T4 that causes.Measure at voltage measuring apparatus 510 and cross over divert shunt resistor R
svoltage after certain time, change or modulate positive driving voltage V+ to reflect secondary current I
s.More particularly, positive driving voltage V+ is changed when driving voltage V+ is applied to secondary 504 with by secondary current I
sin maintenance level maintain in predetermined margin.Result is DC electric current I
dCfor accurate current time high is measured and DC electric current I
dCfor low power dissipation time low.
Fig. 6 is the process flow diagram 600 of the example of method for measuring electric current, and it comprises: step 602: make DC electric current by the primary side of transformer; Step 604: with the primary side of AC voltage driven transformer; And step 606: during maintenance level, measure secondary current, wherein through measuring electric current instruction DC electric current.
Although describe the illustrative of current sensor in this article in detail and currently preferred embodiment, but should be understood that and otherwise differently can embody and adopt described concept and wish appended claims to be interpreted as this type of modification comprised except being limited by prior art.
Claims (26)
1., for measuring a method for electric current, described method comprises:
Make DC electric current by the primary side of transformer;
Use the primary side of transformer described in AC voltage driven; And
During maintenance level, measure described secondary current, wherein said through measure electric current indicate described DC electric current.
2. method according to claim 1, wherein drives the described primary side of described transformer to comprise:
The amplitude of described AC voltage is increased in response to the increase of described secondary current; And
The described amplitude of described AC voltage is reduced in response to the decline of described secondary current.
3. method according to claim 1, wherein drives the described primary side of described transformer to comprise:
The frequency of described AC voltage is increased in response to the decline of described secondary current; And
The described frequency of described AC voltage is reduced in response to the increase of described secondary current.
4. method according to claim 1, the Part I magnetization of the circulation of wherein said AC voltage is described secondary and Part II that the is described circulation of wherein said AC voltage drives described transformer towards saturated.
5. method according to claim 4, wherein during the described Part II of the described circulation of described AC voltage described secondary in described electric current be limited to predetermined value.
6. method according to claim 4, wherein said secondary in described electric current be limited to the value of the saturation current being less than described transformer.
7. method according to claim 4, wherein said secondary in described electric current be limited to the value of the described saturation current being approximately described transformer.
8., for measuring a method for electric current, described method comprises:
Make DC electric current by the primary side of the first transformer;
Make described DC electric current by the primary side of the second transformer;
The first driving voltage is used to drive the primary side of described first transformer;
Use the second driving voltage to drive the primary side of described second transformer, described second driving voltage has the polarity contrary with described first driving voltage;
One in second subprime electric current in the described primary side of the first secondary current in the described primary side of wherein said first transformer or described second transformer reaches maintenance level; And
The described one in described first secondary current or described second subprime electric current is measured during described maintenance level.
9. method according to claim 8, wherein drives the described primary side of described first transformer and drives the described primary side of described second transformer to comprise and make the one in described first transformer or described second transformer saturated.
10. method according to claim 8, it comprises further and to change described first driving voltage and described second driving voltage in response to described measurement to maintain described maintenance level.
11. methods according to claim 10, it comprises further dropping in response to the one in described first secondary current or described second subprime electric current, lower than predetermined level, described first driving voltage and described second driving voltage is maintained predetermined level place.
12. methods according to claim 8, it comprises further:
The amplitude of described first driving voltage and the amplitude of described second driving voltage is increased to maintain described maintenance level in response to the one in described first secondary current or described second subprime electric current increases; And
The described amplitude of described first driving voltage and the described amplitude of described second driving voltage is reduced in response to the one in described first secondary current or described second subprime electric current declines.
13. methods according to claim 11, the one Linear proportional in the described amplitude of wherein said first driving voltage and the described amplitude of described second driving voltage and described first secondary current or described second subprime electric current.
14. methods according to claim 8, wherein said first driving voltage and described second driving voltage are AC voltage, and described method comprises further:
The frequency of described first driving voltage and the frequency of described second driving voltage is increased in response to the one in described first secondary current or described second subprime electric current declines; And
The described frequency of the described frequency and described second driving voltage that reduce described first driving voltage in response to the one in described first secondary current or described second subprime electric current increases is to maintain described maintenance level.
15. 1 kinds of DC current sensors, it comprises:
Transformer, it has primary side and primary side, and wherein said DC electric current is by described primary side;
Driving voltage source, it is coupled to described primary side, and wherein said driving voltage source is secondary for using described in AC voltage driven;
Current monitor, it for measuring described secondary current during the cycle when the secondary current of described secondary middle flowing is in maintenance level.
16. DC current sensors according to claim 15, wherein said current monitor comprises sampling and holding circuit.
17. DC current sensors according to claim 15, wherein said first driving voltage changes to maintain described maintenance level in response to described secondary current.
18. DC current sensors according to claim 15, the amplitude-frequency response of wherein said driving voltage in described secondary current increase and increase to maintain described maintenance level, and the described amplitude-frequency response of wherein said driving voltage in described secondary current decline and reduce.
19. DC current sensors according to claim 15, the frequency response of wherein said driving voltage declines in described secondary current and increases, and the described frequency response of wherein said driving voltage increases in described secondary current and declines.
20. DC current sensors according to claim 15, a part for the circulation of wherein said driving voltage drives described transformer towards saturated.
21. 1 kinds of DC current sensors, it comprises:
First transformer, it has primary side and primary side, and wherein said DC electric current is by described primary side;
Second transformer, it has primary side and primary side, the described primary side series coupled of wherein said primary side and described first transformer;
First driving voltage, it is coupled to the described primary side of described first transformer, and wherein said first driving voltage is for using the described primary side of the first transformer described in an AC voltage driven;
Second driving voltage, it is coupled to the described primary side of described second transformer, and wherein said second driving voltage is for using the described primary side of the second transformer described in the 2nd AC voltage driven, and a wherein said AC voltage is supplementing of described 2nd AC voltage; And
Current monitor, it for measuring described secondary current during the cycle when the secondary current flowed in the described primary side at least described first transformer or described second transformer is in maintenance level.
22. DC current sensors according to claim 21, wherein said current monitor comprises sampling and holding circuit.
23. DC current sensors according to claim 21, wherein said first driving voltage and described second driving voltage change to maintain described maintenance level in response to described secondary current.
24. DC current sensors according to claim 21, the amplitude-frequency response of wherein said first driving voltage and described second driving voltage in described secondary current increase and increase to maintain described maintenance level, and the described amplitude-frequency response of wherein said first driving voltage and described second driving voltage in described secondary current decline and reduce.
25. DC current sensors according to claim 21, the frequency response of wherein said first driving voltage and described second driving voltage declines in described secondary current and increases, and the described frequency response of wherein said first driving voltage and described second driving voltage increases in described secondary current and declines.
26. DC current sensors according to claim 21, are wherein driven into saturated by described first driving voltage or described second driving voltage by described first transformer or described second transformer.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US201461931373P | 2014-01-24 | 2014-01-24 | |
| US61/931,373 | 2014-01-24 | ||
| US14/592,346 US9817031B2 (en) | 2014-01-24 | 2015-01-08 | Magnetically coupled DC current sensor |
| US14/592,346 | 2015-01-08 |
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| CN104808036A true CN104808036A (en) | 2015-07-29 |
| CN104808036B CN104808036B (en) | 2019-11-29 |
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| CN201510036098.0A Active CN104808036B (en) | 2014-01-24 | 2015-01-23 | Magnetic coupling DC electric current sensor |
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| US5552979A (en) * | 1993-11-30 | 1996-09-03 | Philips Electronics North America Corporation | Isolated current sensor for DC to high frequency applications |
| EP2064923B1 (en) * | 2006-09-07 | 2011-12-21 | Philips Intellectual Property & Standards GmbH | Resonant driver with low-voltage secondary side control for high power led lighting |
-
2015
- 2015-01-08 US US14/592,346 patent/US9817031B2/en active Active
- 2015-01-23 CN CN201510036098.0A patent/CN104808036B/en active Active
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0691544A2 (en) * | 1994-07-05 | 1996-01-10 | Vacuumschmelze Gmbh | Current sensor using the compensation principle |
| US5811965A (en) * | 1994-12-28 | 1998-09-22 | Philips Electronics North America Corporation | DC and AC current sensor having a minor-loop operated current transformer |
| CN1741361A (en) * | 2004-08-27 | 2006-03-01 | 三星电子株式会社 | Supply unit and method |
| CN102866283A (en) * | 2012-09-12 | 2013-01-09 | 北京东方计量测试研究所 | Superimposed large-current bias alternative-current (AC) current measuring device |
Also Published As
| Publication number | Publication date |
|---|---|
| US20150212116A1 (en) | 2015-07-30 |
| CN104808036B (en) | 2019-11-29 |
| US9817031B2 (en) | 2017-11-14 |
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